Display screen or portion thereof of a device with transitional graphical user interface



FIG. 1 is a front view of a first image of a display screen or portionthereof of a device with transitional graphical user interface;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof; and,

FIG. 5 is a front view of a fifth image thereof.

The broken line shown in FIGS. 1-5 is included for the purpose ofshowing a portion of a display screen and forms no part of the claimeddesign.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-5. The process or period in whichone image transitions to another image forms no part of the claimeddeign.

CLAIM The ornamental design for a display screen or portion thereof of adevice with transitional graphical user interface, as shown anddescribed.